1. Field of Invention
This invention relates generally to an electronic telephone directory having a data base in which is entered the telephone number codes of the listed parties, and more particularly to a module in which an electronic telephone directory is combined with a dialer adapted to convert the telephone number code of a selected party into corresponding dial tones, the module making it possible for a user to automatically dial any party listed in the directory by means of a dial tone telephone set without having to dial the telephone number code of the selected party on the keyboard of this set.
2. Status of Prior Art
A conventional telephone directory is a book, usually in loose-leaf form, containing an alphabetical listing of the names, addresses and telephone number codes of persons, organizations and firms of interest to those for whom the directory is intended. Thus when a user of the directory wishes to call any listed party, he must first consult the directory to obtain the telephone number code of this party, say 212-986-2480, and then manually dial this number on his telephone set.
Conventional telephone directories have many practical drawbacks. When a user wishes to call a particular party and needs to consult the directory to obtain his telephone number code, the telephone directory book may not then be next to the telephone set, and may be difficult to locate. And since the listings in the directory are usually hand written, they may be difficult to read. Moreover, where it comes to dialing a listed telephone number code, because this code when it includes an area code then has 10 digits, it is easy to make a dialing mistake, making it necessary to redial.
Also when the user of the directory is away from his home or office where he keeps the telephone directory book, he does not have it available to consult when making a call from a remote location.
Telephone sets now in use are mainly of the dial tone type, referred to by the Bell System as a "Touch-Tone" telephone. In a set of this type, the telephone number code of the party being called is entered by the user into a keyboard operatively coupled to a tone generator adapted to convert the number code into corresponding tones. Each digit in the number code is converted in the tone generator to a pair of audio frequencies which are simultaneously transmitted over the telephone line to which the set is coupled.
Thus the digit 5 is signaled by the transmission of 772 Hz and 1335 Hz tones. And digit 3 is transmitted by 697 Hz and 1,477 Hz tones. Because these tone pairs lie in the voice frequency range, they can be transmitted over the telephone line. And they can also be used for purposes besides dialing in other data communication applications.
It is known to provide electronic telephone directories capable of producing dial tones corresponding to a telephone number code listed in the directory. Thus the 1996 patent to Talvard et al. U.S. Pat. No. 5,583,919 notes that it is known to provide a telephone dialer and directory having "an alphanumeric keyboard and a small loudspeaker enabling dual-tone multifrequency (DTMF) dialing signals to be emitted corresponding to various digits of a telephone number."
The 1996 U.S. Pat. No. 5,557,662 to Kenmochi et al. notes that "Conventional so-called electronic telephone directories store telephone numbers and names in pairs. The user can search the telephone numbers and select one of such previously-stored telephone numbers, by manipulating the keys provided on the electronic telephone directory. When a start key is depressed, the electronic telephone directory generates acoustic tones (BP tones) corresponding to the telephone number on display. Thus the user can make a telephone call without using the keys of the telephone by depressing the start key."
The 1995 U.S. Pat. No. 5,452,352 to Talton discloses an automatic dialing system in a credit card format. The credit card includes a memory to which telephone numbers are stored, a keyboard to enter the numbers in the memory, a tone generator and a loud speaker. To dial a telephone number using this credit card, the card which emits the dial tones of the telephone number code to be called, is brought against the transmitter of a standard touch-tone telephone set.
Also in a card format for automatic dialing is the calling card shown in the 1995 McGuire U.S. Pat. No. 5,455,857. As in the above patents, audible dial tones representing a telephone number are generated by the card. Along the same lines is the telephone dialer card disclosed in the 1994 Bazemore et al. U.S. Pat. No. 5,377,263.
As pointed out above, a telephone directory, in order to be useful, must be available to its user when he wishes to make a call. A directory which is not next to the telephone set or cannot be found, serves no useful purpose.
The electronic telephone directories and dialers disclosed in the above-identified patents are independent of the dial-tone telephone sets in connection with which they are useful. Hence if the electronic telephone directory is misplaced, it cannot be brought next to the transmitter of the telephone set to emit dial tones for dialing a selected telephone number code.
Another drawback of existing electronic telephone directories and dialers is that they depend on batteries as their power source, and therefore cease to function when these batteries are run down or exhausted. With an electronic telephone directory that is put to frequent use, the user may find that the batteries are no longer effective just as he is about to make a call. While these batteries may be replaced or recharged, the availability of the directory is then interrupted.
Yet another drawback of known types of electronic telephone directories is that it takes a fair amount of time and effort to correctly enter into the data base or memory of the directory all of the parties to be listed therein. If the user of this directory has in his home or office several touch-tone telephone sets at different sites, and he also wishes to consult the directory at telephone sets away from his office or home, he requires for this purpose several like electronic telephone directories. It becomes necessary therefore to enter into these additional directories the many listings entered into the first directory, a time consuming and tedious task.